AIB, you have to crate a BACS (British) formatted file and send (post) it to First Trust in Northern Ireland. This may have changed, but I don't think so.
BOI, you can send an Irish EMTS formatted file with British Accounts (not mixed) via their WinBITS/Internet site and they will forward it into BACS.
UB, they have replaced their Irish Internet system with the RBS one, this will allow full international (not just the SEPA area) credit payments (BICS, IBANs etc), via a CSV file.